There's been a fair amount of discussion about the particular vices of the Osprey in Rotorheads - a search over the last few years should trawl up a fair amount of info.
The single engine failure case shouldn't be too much of a problem as, has been described, there are drive linkages between the engines.
However, asymmetric vortex ring is much more of a worry - especially at low level. But I'm not tilt-rotor pilot, read the threads and judge for yourselves.